The embodiments described herein relate generally to a device used in conjunction with an ultrasonic ablation device, and, more specifically, to a transmission member configured to transfer ultrasonic energy to a bodily tissue (including an occlusion, kidney stone or the like) from an ultrasonic energy source.
Known ultrasonic energy transmission systems are used in many different medical applications, such as, for example, for medical imaging, to disrupt obstructions and/or to ablate bodily tissue. In known ultrasonic energy transmission systems for tissue ablation, ultrasonic energy is transferred from an ultrasonic energy source through a transducer horn and then a transmission member, such as a wire, to a distal head. Ultrasonic energy propagates through the transmission member as a periodic wave thereby causing the distal head to vibrate. Such vibrational energy can be used to ablate or otherwise disrupt bodily tissue, for example, a vascular obstruction, a calculus, such as a kidney stone, or the like.
Some known devices for the removal of a calculus include an ultrasonic probe (or transmission member) used to apply ultrasonic energy for fragmentation and removal of the calculus. In some known methods, the ultrasonic probe is placed into contact with the calculus (in the urinary tract, for example) and is then used to deliver ultrasonic energy to fragment the calculus. The calculus fragments are then aspirated out of the body through a lumen of the probe. However, the calculus and calculus fragments often clog the opening of the lumen. Additionally, it can be difficult to maintain contact between the distal end of the probe and the calculus, reducing the efficiency of the ultrasonic energy delivery. Moreover, the failure to maintain the position of the calculus can also result in proximal (or “backward”) migration of the calculus and/or fragments thereof. For example, known methods of ablating a calculus within the ureter can produce migration of the calculus towards the kidney, which can necessitate additional procedures.
Some known devices have attempted to solve the problem of the lumen clogging during aspiration by defining a slot or secondary opening extending from the primary lumen opening. In such arrangements, smaller calculus fragments can be aspirated through the slot even if the primary opening is clogged. Even with these designs, however, it remains difficult to control the location of a calculus relative to the probe openings, and so the fragmentation remains inefficient, and the possibility of undesirable migration of the calculus and fragments exists.
Some known devices for the disruption of bodily tissue include a basket for maintaining the position of and retrieving a calculus from a bodily lumen. For example, some known procedures for removing calculi in the ureter include placing a small tube, known as a ureteroscope, in the ureter. Next, a basket is extended from the ureteroscope and collects the calculus. Optionally, if the calculus is large it can be fragmented using, for example, a laser device, ultrasonic device or the like. Finally, the ureteroscope, the basket, and the calculus are removed from the ureter. However, this process can be time consuming and can require complicated manipulations with the instrument.
Some known devices for breaking up bodily occlusions include sharp distal ends. However, unlike in vascular procedures where a sharp tip may be desirable to break up or pass through an occlusion, sharp tips should be avoided in ureteral procedures. Sharp tips have a high risk of puncturing the ureter. Additionally, calculi within the ureter (i.e., kidney stones) are not usually able to be broken up by sharp probe tips.
Thus, there is a need for improved devices for ablating an occlusion that can limit the movement of the calculi during the procedure.